A lane changing assistant of this kind is known, for example, from German Published Patent Application No. 101 14 187, and is used in connection with a speed control system, for instance, a so-called ACC system (Adaptive Cruise Control), which is not only in a position to regulate the speed of the vehicle to a speed desired by the driver, but is also in a position to adjust the speed of one's own vehicle, if necessary, to the speed of the preceding vehicle, so that the latter is being followed at a suitable safety distance. For this purpose, a surroundings sensor system is present, for example, in the form of a radar sensor, using which the distances and also the relative speeds of preceding vehicles may be measured. Such ACC systems are particularly provided for travel on multi-lane expressways or Autobahns.
The lane changing assistant is used to make it easier for the driver to change to an adjacent lane, for instance, when he wishes to start on a passing procedure.
The lane changing assistant known from the abovementioned document is developed in such a way that, when a lane changing request by the driver is detected, it automatically initiates an acceleration procedure, so that pulling into the flowing traffic in the adjacent lane is made easier. The target speed or passing speed to be reached in this acceleration procedure, in this context, depends not only upon the speed of the vehicle, that is to be passed, proceeding ahead in one's own lane, but also upon the speed of one or more additional vehicles that are located in the adjacent lane, ahead of one's own vehicle. In this manner, one is able to avoid running up too closely to the vehicle in the adjacent lane.
A passing intention by the driver is recognized by the known system in that, for example, the driver activates the respective direction indicator (blinker). When the passing intention is recognized, the acceleration procedure is then triggered immediately.
In the same document the possibility is also mentioned that one might, for example, monitor the traffic following in the adjacent lane, using a rear-facing radar, and, when the follow-on traffic permits a passing procedure, to suggest a passing procedure to the driver automatically, by a suitable signal, which the driver may then confirm or not confirm.
Furthermore, lane changing assistant systems such as blind spot warning systems are known which, with the aid of the surroundings sensor system, record the adjacent lane at the side of the vehicle and behind the vehicle, and warn the driver optically, acoustically or haptically when there is a lane change and a vehicle is located in the blind spot. However, the emission of such a warning signal may be disturbing to the driver, may be overlooked or may be wrongly interpreted by the driver.